Personal location data is valuable to facilitating human interactions and thus to social networking and communications services. For example, a service which lets you know when your friends are nearby would be valuable to many people. If you land in another city for a meeting, you may enjoy dining with a close friend who also happens to be visiting the city, rather than dine alone. Yet privacy concerns mean most people are reluctant to share location data freely. Thus, even though some mobile apps (e.g., Apple's Find Friends) already have the functionality to see where friends are located, the privacy cost of always-on location sharing is so high that most iPhone users do not share their location through the app and those who do share with only a very small number of close friends and family.
Likewise, a service which lets you know when your friends are conveniently available for an audio call or videoconference would be valuable to many people. For instance, while driving to work, it would be desirable to have a phone conversation with a friend or work contact who also happens to be stuck in a car and thus is conveniently available. But nobody has been able to develop a widely-adopted service which reports what your friends, family, or work contacts happen to be doing and whether they are available at the same time you are because privacy concerns mean most people are reluctant to share their availability status freely. More generally, it may be valuable to know when other people have any matching personal data, such as political affiliation, sexual orientation, or unusual interests.
In addition to the “always on” personal data sharing services such as Apple's Find Friends, there are also “single opt-in” services. For example, a user can choose to broadcast their location by posting a message or photo, or “checking in” on a social network, knowing that the post will be seen by many of their friends through the social network. The drawbacks in using these services to solve the location sharing problem are 1) that they require effort on the part of the user to remember to create and then to create the post, and many users are too busy to remember to take the time to create the post, 2) many users feel that posting about travel is “showing off” and so avoid doing in spite of the benefit of potentially meeting other friends there, 3) users of social networks may perceive that those who do post their travel are over-sharing and are thus socially less desirable, 4) such posts require affirmative effort and many users would only use a service that is more automatic, and 5) such posts may lead to awkwardness if a contact sees it and responds that they would like to meet up, but the user of the original post would rather not meet that contact.
There further exist “double opt-in” services such as dating apps that only establish connection for messaging between two users who have selected each other. Some dating apps offer to match users with a selection of other users within geographic proximity and with whom they are already connected through social networks. However, these do not solve the problem of connecting with friends and business acquaintances, because there is no feature to monitor connected users' location and notify a user when one of their connections becomes geographically proximate. Worse, these apps have a more serious drawback in that they do not protect privacy. That is because, when a user uses a geographic filter, that user knows any other user displayed by the app is certainly nearby.
The significant interest that individuals have to know when their friends, family, business contacts, and other contacts are nearby and to facilitate convenient meetings, together with the fact that none of the foregoing apps and other technology solutions have taken off due to privacy concerns demonstrates the long-felt need for a privacy-protecting solution. In addition, the significant benefit from being able to reach friends, family, business contacts, and other contacts at a mutually-convenient time demonstrates the long-felt need for a privacy-protecting solution for sharing personal data more generally. There has not yet been a technology solution to address the aforementioned shortcomings of conventional personal data sharing services. I have found that the technology problem to be solved is to find a means to share and match on personal data while protecting users' privacy.